Acoustical ceiling construction



July 30, 1935- J. s. OFFUTT El AL ACOUSTICAL CEILING CONSTRUCTION Filed Nov. 12, 1931 2 Sheets-Sheet 1 INVENTORS J4 ME5 5.0FFUTTI CaleL 5. 5T/E0M. M22

7 A-i-roRNE July so, 1935. J. 5. QFFUTT El AL 2,009,512

ACOUSTiCAL CEILING CONSTRUCTION I Filed Nov. 12, 1931 2 Sheets-Sheet 2 sr WM TF0 N NFE R ar 0 wa n .A Mm ham Patented July 30, 1935 UNITED STATES PATENT OFFICE 2,009,512 ACOUSTIOAD CEILING CONSTRUCTION James S. Offutt and Carl S. Stro n, Chicago, Ill. Application November 12, 1931, Serial No. 574,524

This

tions, and has reference more particularly to building constructions for acoustical purposes in preventing the reflection of sound from a ceiling.

In the construction of acoustical ceilings of the type employing a perforated metal membrane backed by sound absorbing layers, some dlmculty has been experienced in erecting the ceiling due to high labor cost resulting from faulty attachmerit of the perforated membranes. It has heretofore been dificult to maintain the lower faces of the result that uneven light reflection from the membrane caused the lower surface of the ceiling to have objectionable high lights and poor appearance.

membrane in a single plane, with the The acoustical ceilings heretofore proposed commonly placed the sound absorbing material directly upon the membrane,

Another object of the invention is to providean acoustical ceiling construction in which the bottom faces of the perforated membranes lie in a single plane so that light reflection is uniform from all the membranes.

A further object of the invention is to provide a quickly erected acoustical building construction in arated a substantial distance from the membrane which the fibrous absorbing layer is septo permit the lower surface of the membrane to be washed effectively; also to improve building constructions in other respects hereinafter speci lied and claimed.

Reference is to boiled to the accompanying drawings forming a part of this specification, in

- which further modified form of ceiling construction,

Fig. dis a perspective view of a still further modified form of ceiling construction. I

Our improved acoustical ceiling is characterized in that it can be easily installedin either old or new buildings. The ceiling proper to may 5 consist of metal lath and plaster, plasterboard or any other type of ceiling desired. The ceiling HI is supported in the usual fashion from joists not shown, and is supported around its edges by walls H which may also be of any desired con- 10 struction. Flexible H shaped rails I2 .or other suitable support bars or runner means are suspended a substantial distance below the ceiling I0 by means of quickgripping clamping brackets E3 or any other suitable means. The brackets i3 15 are preferably non-continuous and are preferably formed of a piece of strap, cold rolled steel .com-' posed of two integral legs 54 L-shaped in contour and having U shaped clamps [5 formed on the bottom end of each leg for engaging upper rail 20 flanges [6 which are formed on a web I? of the rails i2. An outstanding horizontal flange formed on the clamping bracket it may be secured by expansion or toggle bolts ii to the ceiling i0. 25

In order to cause the clamps l5 to tightly grip the flanges IS, a connecting bar or rod i8 preferably spans the distance between adjacent rails l2, said bar 18 being preferably provided on each end with a U shaped return bent clamp l 9, which 30 is arranged to embrace the downwardly extending clamping legs M. A U shaped catch 20 is formed on the outer leg 2| of the clamp 19. When installing, the legs of the clamp 19 spread slightly to grip the clamp leg it until catch 28 snaps over 35 the forward edge of one of the clamp legs M. An integral lug 22 is struck outwardly from one .of the legs ll, so as to engage the top edge of clamp leg 2| and prevent said clamp leg from being inadvertently raised out of clamping position after erection.

A pad of light weight material 23, preferably of a fibrous nature, such as mineral wool, hair felt or vegetable fiber, is supported by the means 18. The pads 23 are preferably of a width sub- 45 turn bent hoofif diwiiich engages with one of the in which are formed perforations 28. These per-- forations may be triangular in shape as shown, or may be any other desired shape, such as round or slotted, to harmonize with the finish used in any room to be equipped with the acoustical ceiling. The membrane 21 is preferably formed of a light weight, tin-plated, non-tempered iron, or

. aluminum, but any suitable metal or non-metal may be used if desired. It is important that the membrane 21 be perfectly flat, so that when paint or other decorative surface is applied to the lower face of the membrane, no high lights or objectionable markings will be seen by people occupying the room containing the acoustical ceiling, The membrane 21 may be square or rectangular in shape, or, in fact, any other desired shape, and the edges thereof are turned upwardly at an angle to form bevel 29, and are then bent vertically upward to form vertical flanges 30 which abut one against the other at the edges of adjoining membranes to accurately align, said membranes. The membranes 21 with their upturned edges are preferably formed accurately by means of dies so that the distance between the top of the flanges 30 and the bottom face of the membranes is exactly uniform on all of the membranes. The top edges of the flanges 30 preferably abut against bottom flanges 3| formed on the rails 12.

In order to support the membrane 21 with the upper edges of flanges 30 tightly abutting against the rail flanges 3|, we provide a plurality of spring clips 32 which are preferably tempered metal, which curve downwardly toward the upper face of the membrane 21 to form a shoulder 33, which is preferably spot welded to.

the inner face of the membrane 21. Inside of the shoulder 33, the spring clip 32 has an upwardly extending loop 34, which again extends downward to form a clip end 35 which engages against the upper face of the membrane 21. The attaching or outer end of the clip 32 preferably extends slightly downwardly to forma shoulder 36 which contacts with the upper face of rail flanges 3| with a substantially single line contact, and said clip then is formed upwardly to form a flange Triangular holes 28a are also preferably formed in the spring clip 32 adjacent the shoulder 33 so that said openings 28a register with corresponding openings in the membrane 21, thus making the clips invisible from the bottom face of said membrane.

It will be seen that the spring clips 32 have a tendency -to lift the'weight of the center of the membrane 21 adjacent shoulder 33 and thus counteract the weight of the membrane and prevent it sagging down out of an exact plane surface as it impinging sound waves and increase the overall sound absorbing efficiency of the ceiling construction. It will also be noted that a considerable clearance is allowed between the upturned flanges 31 on the spring clips and the web I1 of the rails so that exact spacing of the rails is not necessary and the cost of erection is, therefore, considerably reduced, In the construction described a considerable space 38 is provided between the membrane 21 and pad 23, and the sound waves entering this space through the perforations 28 are partially absorbed and mixed together in this space to increase the overall sound absorbing efficiency of the construction. The membranes 21 are preferably provided with suflicient of the perforations 28 so that the area of the perforations constitutes about 8 to 15 per cent of the total area of the membranes. With this area of perforations, approximately 90% of the incident sound will pass through the perforations into the space 38 to be absorbed by the pad 23.

The modified form of ceiling construction shown in Fig. 4 is of the same general character as the construction shown in Figs. 1 to 3, except that a modified form of rail 40 is used. The body 4| of the runner or rail 40 is preferably triangular in cross section with a pair of outwardly extending upper flanges 42, which are adapted to be engaged by the clamps l5, as shown in Fig. 4. Spring clip 43 has a flat section 44, which may be spot welded to the upper surface of the membrane 21, and is provided with perforations 45 to register with the perforations in the membrane. The clip 43, which is adapted to permit the membrane 21 to be snapped up from below into engagement with the runner 40, extends upwardly at approximately the same angle as the sides 46 of the triangular shaped rail 4|, and has a shoulder 41 for engaging a side 46.

In the form-of construction shown in Fig. 5, transverse grillage channels 48 are secured below the main ceiling channels 49 by means of wires 50. U shaped wire clamps have oppositely disposed clamps 52, which engage over the upper flanges l8 of a rail l2, similar to that used in the con-v struction shown in Figs. 1 to 3. The legs of the wire clamp 5| may be secured together in clamping position by means of a wire 53 twisted about said legs. The membrane construction used in this form of ceiling is substantially the same as that shown in Figs. 1 to'3.

In the modified form of construction shown in Fig. 6, a rail 54 may be composed of two channels 55 in back to back abutting position, the webs 56 of said channels being spot welded together to form a rigid, unitary rail. Slots 51 are formed'in the web 55 for receiving downwardly extending hooks 58 formed on each end of supporting rods 59. The rods 53 serve to accurately space apart the rails 54 and to also support the sound absorbing pad 23. The upper flanges 55 of the rail 54 may be provided with perforations 30 so that said flanges may be nailed directly to the ceiling. in order to reduce the amount of space between the ceiling and membranes 60a supported by said rail.

Inwardly extending, U shaped, gripping flanges 6| are formed along opposite upturned flanges 62, formed along opposite sides of the membrane 60a. The flanges 6| are arranged to embrace the lower flanges 63 of the rail 54. In installing the membranes 60a, they may be moved longitudinally of the rail 54 by a sliding action with the flanges 6| engaging the flanges 63, or the membranes 6011 may be flexed slightly to slip the flanges GI over the rail flanges 33. If desired the type of membrane shown in Figs. 1 to 3 may be used on the construction shown in Fig. 6.

We would state in conclusion that while the illustrated examples constitute practical embodiments of our invention, we do not wish to limit ourselves precisely to these details, since manitestiy, the same may be considerably varied without departing from the spirit of the invention as defined in the appended claims.

Having thus described our invention, we claim as new and desire to secure by Letters Patent:-

1. In an acoustical ceiling construction, a pinrality of supporting rails in spaced, parallel rela-' tion, perforated membranes positioned below said rails, said membranes having upturned flanges, the upper edges of said flanges abutting the bottom of said rails, resilient means for supporting said membranes on said rails with said flanges in firm contact with the bottom of said rails, and means above said membranes for absorbing sound.

2. In an acoustical ceiling construction, a ceiling, clamping members secured to said ceiling, supporting rails supported by said clamping members in spaced, parallel relation, connecting bars extending transversely between said clamping means, an acoustical absorbing pad supported by said bars, and perforated membranes supported by said rails.

3. In an acoustical ceiling construction, a plurality of supporting rails in spaced, parallel relaso as to support said rails from said surface, locking means for preventing the disengagement of said clamps from said rails, perforated membranes supported by said rails, and acoustical sound absorbing material between said membranes and said surface.

5. In an acoustical ceiling construction, a plurality oi! rails in spaced, parallel relation, said rails having outwardly extending upper flanges,

- acoustical pad supported above said membranes.

6. In an acoustical building construction, a building surface, a'plurality of supporting rails secured to said surface in spaced, parallel relation, a plurality of perforated metal membranes positioned adjacent said supporting rails, spring clips welded to the irmer race of said membranes, and adapted to secure said membranes to said rails,

and means between said membranes and said surface for absorbing sound.

7. In an acoustical building construction, a plurality of elongated support members in spaced, parallel relation, a building surface supporting said support members, a plurality of perforated metallic membranes positionedadjacent said support members, attaching clips secured to each of said membranes intermediate the edgesof said membranes so as to connect said membranes to said support members and sound absorbing material positioned between said membranes and said building surface.

8. An acoustical ceiling construction comprising a plurality of runners, perforated metal, membrane units below said runners, spring clips secured to said units and connecting the same to said runners, rodme'ans spanning adjacent runners, and sound absorptive material carried by said rod means.

9. In a metallic membrane for ceiling construction, a planular body part, upstanding flanges on the sides of said body part, and separate spring clips associated with said membrane to resiliently clip the same to ceiling supports, said clips extending above said flanges and being adapted to retain the edges of said flanges against said ceiling supports.

JAMES B. OFFU'I'I. CARL S. STROM. 

